Light-emitting diodes (LEDs) may be used in illumination apparatus for lighting rooms or other indoor or outdoor areas. Some LED-based illumination apparatus comprise a plurality of LEDs of different colors. Light from each of the plurality of different colored LEDs may combine to yield a composite color. By modulating the intensity of light from each different colored LED, such illumination apparatus may provide light having a range of intensities and colors.
Many existing lighting installations provide AC dimmer switches originally installed to control the brightness of incandescent light sources. The modulated AC line voltage produced by operation of such dimmer switches must typically be processed in order to control a LED-based illumination apparatus.
The inventors have determined a need for improved apparatus and methods for controlling the intensity and color of light emitted from LED-based illumination apparatus.